Saws for cutting concrete, asphalt and the like, etc. are conventionally electrically powered or powered by an internal combustion engine that utilizes gasoline or diesel fuel, the latter of which cannot be used indoors due to the exhaust generated. When concrete saws are powered by electricity, an electric motor of at least 5 horsepower is needed and an internal combustion engine generator is conventionally used to provide the necessary power because the necessary power is usually not conveniently located to the cutting location. However, when indoor cutting is required, the generator due to its exhaust must be operated outside and the time required to run an electrical line, which often is hundreds of feet and/or up a number of stories, can be prohibitedly expensive and also results in resistance power loss in the electrical line.
U.S. Pat. No. 7,000,605 Due discloses a concrete engraver apparatus and method that is normally operated through a power cord that appears in the drawings to be house type 110 volt, but is also disclosed as using a battery pack. This engraver is manually moved much like a carpet vacuum cleaner and does not appear to be sufficiently heavy duty to permit use in heavy duty concrete cutting jobs.
U.S. Pat. No. 4,998,775 Hollifield discloses an apparatus for precision cutting of concrete surfaces that utilizes a battery for powering a self-powered vehicle supported by a pair of spaced tracks. The necessity for spaced tracks for such a concrete cutter would result in any cutting job also being prohibitedly expensive.
Other prior art noted during an investigation conducted for the present invention include U.S. Pat. No. 2,468,336 Lewis; U.S. Pat. No. 4,175,788 Jacobson et al.; U.S. Pat. No. 4,767,162 Reed, III; U.S. Pat. No. 4,824,516 Ishihara et al.; U.S. Pat. No. 5,104,195 Zaccho; U.S. Pat. No. 5,810,448 Kingsley et al.; U.S. Pat. No. 6,102,022 Schave; and U.S. Pat. No. 6,484,711 Acker et al; and also include United States Published Patent Applications: 2002/0117160 Acker et al; 2003/0168054 Governo et al; and 2007/0164598 Johnson et al.